Problem Solving Tree(ENG)

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Problem Solving Toolbox- 5 Why - Is-Is Not Matrix

- Problem Solving Tree

Problem Solving Tool box --- 5 Why

5 Why

Linkage between 5-Why & 5-Step? ? 5-Why is a Root-Cause-Analysis tool 5-Step is a Problem-Solving-ProcessStep 1: Identify and define the problem. Step 2: Take immediate action to prevent the problem from reaching the customer. Step 3: Identify the root cause of the problem. Step 4: Take irreversible corrective action to eliminate or minimize the effects of the root cause of the problem. Step 5: Verify that the corrective action is effective.

5-Why works here

5 Why

AN EMPLOYEE REPORTED A BROKEN ARM.

WHY DID THE PROBLEM OCCUR?

Why 1: Why 2: Why 3: Why 4: Why 5: Why 6:

Stumbled and fell on lobby stairs. Forgot to use hand rail. Was mentally agitated when came to work. Argued with wife over Mother-in-law’s visit. Mother -in-law visited for a week. Wife loves her mother.

5 Why

Like a detective, we find the Root Cause by asking questions. Like a detective, we start with the end of the trail and work backwards. We start with the Problem.

Where did you hide the Root Cause?

5 Why

In the Delphi organization, a common 5-why Root Cause Analysis is used to analyze and solve quality problems. There are four major parts of the 5-why Root Cause Analysis process:? ? ? ?

5 Why Part 1: Understand the situationDuring the first part of the process, you:Identify the Problem Clarify the Problem Breakdown the Problem Locate the Point of Cause (PoC) Grasp the significance of the problem

Part 2: Cause InvestigationIn the second part of the process, you: Conduct a “5-Why” investigation to identify the root causefor the specific problem For why the problem was not detected for why the “system” allowed the problem to occur

5 Why Part 3: Problem CorrectionIn the third part of the process, you: Take specific action to correct the problem(s). At a minimum, short-term temporary measures are required to protect the customer.

Part 4: Prevention through error proofingIn the fourth part of the process, you:Take specific action to make sure the problem cannot recur, typically through error proofing Capture and communicate Lessons Learned

5 Why?Investigation of Root CauseWhy did we have the problem? Why did it get to the customer? Why did our “system” fail?

Root Cause Corrective Action

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Lessons Learned

5 Why-Understand the situation Step 1Identify the problem:In the first step of the process, you become aware of a problem that may be large, vague, or complicated. You have some information, but do not have detailed facts. Ask:What do I know?

Step 2Clarify the problem:The next step in the process is to clarify the problem. To gain a more clear understanding, ask: What is actually happening? What should be happening?

Step 3Break down the problem:At this point, break the problem down into smaller, individual elements, if necessary. What else do I know about the problem? Are there other sub-problems?

5 Why-Understand the situation Step 4Locate the Point of Cause (PoC):Now, the focus is on locating the actual point of cause of the problem. Where in the process is the problem occurring? You need to track back to see the point of cause first-hand. Ask: Where do I need to go? What do I need to see? Who might have information about the problem?

Step 5Grasp the Significance of the Problem:To grasp the significance of the problem, ask: When? Where? What? How often? How much?

It’s Important To Ask These Questions Before Asking “WHY”?

5 Why-Cause Investigation Step 1Identify and confirm the direct cause of the abnormal occurrenceIf the cause is visible, verify it. If the cause is not visible, consider potential causes and check the most likely causes. Confirm the direct cause based on fact. Ask: Why is the problem occurring? Can I see the direct cause of the problem? If not, what do I suspect as potential causes? How can I check the most likely potential causes? How can I confirm the direct cause?

Step 2Use 5-Why investigation to build a chain of cause/effect relationships that lead to the root cause. Ask:Will addressing the direct cause prevent recurrence? If not, can I see the next level of cause? If not, what do I suspect as the next level of cause? How can I check and confirm the next level of cause? Will addressing this level of cause prevent recurrence?

5 Why-Cause Investigation If not, continue asking “Why?” until you find the root cause.Stop at the cause that must be addressed to prevent recurrence. Ask:Have I found the root cause of the problem? Can I prevent recurrence by addressing this cause? Is this cause linked to the problem by a chain of cause/effect relationships that are based on fact? Does the chain pass the “therefore” test? If I ask “Why?” again, will I be into another problem?

Be sure you have used 5-Why Investigation to answer these questions:Why did we have the specific problem? Why did the problem get to the customer? Why did our “system” allow the problem to occur?

Use temporary measures to eliminate the abnormal occurrence until the root cause can be addressed. Ask: Does it contain the problem until a permanent solution can be implemented?

5 Why-Prevention through Error Proofing Implement corrective actions to address the root cause:For the specific problem For why the problem was not detected For why the “system” allowed the problem to occur

ASK: Does it prevent the problem fromhappening again? Follow-up and check results. Ask:Is the solution working? How do I know?

Capture and communicate lessons learned.

5 Why-Check List To be sure you have followed the problem solving model, use this checklist as you complete the problem solving process.

Part 1: Understand the situation_ _ _ _ _

Identify the problem. Clarify the problem. Break down the problem. Locate the Point of Cause (PoC). Grasp the significance of the problem.

Part 2: Cause investigation_ _ _ _

Identify/confirm the direct cause. Ask 5 Why’s to identify the root cause. Ask 5 Why’s for “Why the problem was not detected and reached the customer?” Ask 5 Why’s for “Why the system allow the problem to occur?”

5 Why-Check List To be sure you have followed the problem solving model, use this checklist as you complete the problem solving process.

5 Why-Case StudyACTIVITY: FLEX INDUSTRIES CASE STUDYDirections: ? Use the Delphi 5-Why Root Cause Analysis to evaluate the Flex Industries Case Study below and on the following pages. Review the 5-Why analysis template to record your information. ? Use only the information provided in the case study to complete the 5-Why. ? Do not try to re-engineer the rivets or solve the technical problems in the case study. The purpose of this activity is to use the 5-why template to organize the given data and uncover the true root cause(s). FLEX INDUSTRIES CASE STUDY Key Players Jake Janet Sam Judy Ben Quality Manager CSE, Winding River Plant Team Leader, East Line QA Auditor, East Line Machine Operator

5 Why-Case StudyBackground Jake Ryan is the Quality Manager at Flex Industries. Flex is a component supplier that manufactures metal stampings and light assembly products. The company has a reputation for supplying high quality parts on a consistent basis. Seldom has there been a customer complaint. Flex has Quality representatives called Customer Support Engineers (CSE’s) at every customer assembly plant. The CSE’s report any problems to Jake for investigation and follow-up. At 7:00 a.m. this morning, Jake received a call from Janet, CSE at the Winding River Assembly Plant. Janet informed him that the customer had found five defective stabilizing brackets on second shift last night. She checked the remaining inventory and there were no defects in the remaining 326 pieces. The manufacturing sticker on the back of the brackets indicated that they were made by the second shift operator. Normally, the stabilizing bracket is fastened to the regulator motor with three rivets. The five defective brackets had only two rivets in them. The lower set of rivets on all five brackets was missing a rivet. This could only happen if the automated rivet machine did not place rivet in position . This was the first time that the problem occurred.

5 Why-Case Study

Good

Bad

Jake set-up containment procedures at the plant warehouse to sort for discrepant materials. As of this morning, two more defective brackets had been found in the remaining 2019 pieces of inventory at Flex.

5 Why-Case StudyCause Investigation Jake went out to the floor to talk with the team leader of the two rivet lines (East and West) and the area quality assurance auditor. He informed Sam (the team leader) of the quality problem and asked him to identify the line that ran the stabilizing bracket assembly. Sam directed Jake to the East line which ran Winding River assembly brackets only. At the East Line, he spoke with Judy (the QA Auditor for the area) and asked to see the quality log sheets. Jake and Judy reviewed the Nov. 11th log sheet and could not find anything out of the ordinary. He asked Judy to set-up in-house containment procedures to sort for any discrepant material in the finished goods area. Then Jake looked at the control plan to see what the requirements were for checking the bracket. The only required check was to do a dimensional verification at machine set up. Jake decided the next thing to do was to go to the document control center and look at the PFMEA for the bracket. He needed to find out what failure modes were called out on the PFMEA for missing rivets, thinking this might help him in his investigation. Unfortunately, the only failure mode called out on the PFMEA for missing rivets was poor set-up, and he already knew the set-up for the bracket had been approved. He even had a sample part from the set-up and the rivets looked fine.

5 Why-Case StudyNext, Jake tried to locate the second shift operator whose clock number was on the defective parts. Since that operator was gone, Jake spoke with the current machine operator (Ben). He asked Ben about any recent difficulties with the rivet machine. Ben said that he hadn’t noticed anything out of the ordinary. Ben also mentioned, however, that there had never been any quality bulletins posted in the two years that this particular part has been running. Jake decided to stay in the area to watch the machine run for a while. After about 15 minutes, he watched Ben dump rivets into the feeder bowl to prepare for the next run. Shortly after restarting the rivet operation, Ben walked over to another riveter and came back with a steel rod. Ben poked around the rivet chute and then continued working. Jake approached Ben and asked him about the steel rod. Ben replied that from time to time the chute gets jammed and he has to clear it out. If the chute got jammed, the automatic machine would fail to load a rivet and place it in position. This happens two or three times during a shift. He didn’t mention this in his earlier conversation with Jake because the problem had existed ever since he started working with this machine. The previous operator showed him how to clear the chute. All the rivet machines were like this according to Ben. Jake called the Machine Repair Department and asked that someone look at the rivet track. A slight gap in the track was found and removed, and Ben continued to work.

5 Why-Case StudyTwo hours later, Jake got a call from Ben saying that the track was still jamming. As far as Jake could see, only rivets were in the bowl. Next, Jake looked into the rivet supplier containers. There was some foreign material in the blue container, but none in the red container. The label on the blue container showed that it was from Ajax Rivet, Inc., and the label on the red container indicated that it was from Frank’s Fasteners. Obviously, the foreign material was entering the rivet feeder bowl and jamming the track. Jake looked at the operator instructions posted on the job to see if there were any instructions about not using containers with foreign material in them, but there wasn’t. Jake called Maintenance and requested that the bowl be cleaned. He also added the cleaning operation to the preventive maintenance schedule on the equipment. He then called both Ajax Rivet, Inc. and Frank’s Fasteners. He asked about the cleaning procedures on the returnable containers. Frank’s did a full container purge and clean. Ajax just re-introduced the containers back into their system. When Jake asked why Ajax did not clean their containers, he was told that Ajax was not aware that such a requirement was needed. It had never been part of the customer requirements document.

5 Why-Case Study

Upon further investigation, Jake learned that Frank’s Fasteners supplied other major automotive companies. Since these companies required that all returnable containers be cleaned, Frank’s instituted the purge as part of its practice for all customers. Ajax Rivet, however, depended primarily on Flex as its major customer. No such requirement had ever been communicated to them. Jake called the Packaging Department and requested that a container maintenance requirement be drafted which would apply to all their suppliers. He also asked that a machine modification be developed to sense for the presence of rivets. Hopefully, this would error proof the process.

5 Why-Case StudyPath to Investigate Specific Nonconformance

AN EXAMPLE - Part A

WHY DID THE PROBLEM OCCUR? A CUSTOMER REPORTED MISSING RIVETS IN A BRACKET ASSEMBLY. Why 1: Why 2: Why 3: Why 4: Why 5:Automated rivet machine did not place rivet in position Feeder had obstruction Rivet supplier dunnage had foreign material Supplier had no maintenance program for dunnage Supplier not aware of foreign material requirement

5 Why-Case StudyPath to Investigate Lack of Detection

AN EXAMPLE - Part BWE NOW KNOW WHY THE PROBLEM OCCURRED. BUT, IS THERE MORE?

WHY WAS PROBLEM NOT DETECTED?

Why 1: Why 2:

No inspection required on Control Plan, except set-up Not identified on PFMEA as failure mode, except set-up

5 Why-Case StudyPath to Investigate system

AN EXAMPLE - Part CWE NOW KNOW WHY THE PROBLEM OCCURRED AND WHY IT WAS NOT DETECTED. BUT, IS THERE MORE?MISSING

1. Make supplier part of APQP activities. 2. Make PFMEA’s comprehensive of entire system

Scope of PFMEA limited to manufacturing process only

C

Problem Solving Tool box --- Is-Is Not Matrix

Is-Is Not Matrix What’s Is-Is Not Matrix??

The Is-Is Not matrix is the first “round” of the Dictionary Game. A powerful tool for specifying a problem and laying out the first clues about its root cause. A matrix to summarize what kind of problem did occur, and what might have occurred but did not; where and when it was observed, and where and when it might have been observed but was not; etc. A useful tool for the first meeting of a problem solving team, because it puts the collective group knowledge on paper and shows what information is lacking and still needs to be collected.

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Why Is-Is Not Matrix??

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It’s the first step toward solving a problem systematically, because it lays out what is already known about the problem, in front of the entire problem solving team. It’s an efficient way in quick shooting the root cause.

Is-Is Not Matrix How to use Is-Is Not?1. 2. 3. 4. 5. 6. 7.

8. 9. 10.

Clearly state the problem at hand, in terms of what the current state is versus what the desired state is. Gather together a team consisting of people who would know something about the problem. Fill out the Is-Is Not form in a group meeting, at least initially. Fill out the “Is Not” column as well as the “Is” column. List any distinctions in the appropriate column. These distinctions can be useful clues. List any changes that might have caused the problem to occur. Changes might be in supplier, raw material, machine, procedure, setting, etc. If at any time, multiple problems seem to be appearing, it is OK to create separate Is-Is Not matrices for them. Tree diagram or cause-and-effect may also be used. Develop action plan to collect any missing information, and to collect data that can back up any hearsay. Assign responsible persons for that. Analyze the completed matrix, try to find out clues. If the problem is not yet solved, develop a problem solving plan based upon the Is-Is Not matrix. Try to incorporate other tools to find Red-X out.

Is-Is Not MatrixTeam Members:

IS WHAT object? What defect? WHERE geographically? Where on the object? WHEN in clock and calendar time? When since ? Any pattern? When in the history/life cycle? HOW MANY objects? How large is a defect? How many per object? What is the trend?

Is-Is Not Matrix-Case StudyBackground Three pieces of Volvo Frond Door harness(P/N: 8697907) were rejected by VCG(Volvo Belgium Plant) respectively on Sep-23-2004, Oct-12-2004 and Oct-15-2004. The reason for rejection is one connector can not be locked with the mating parts. When the final assembly operators at Volvo tried to mate these harness with mating parts, a clear “click” sound could not be heard, and the mating parts could be easily pulled away from each others, which indicated a non-locked connection. The not-locked situation existed after disassembling and reassembling multiple times. The defective harness was originally built at Delphi GZ, then shipped to Delphi Europe, then transported to Volvo’s plants. Delphi GZ is building both Volvo Front Door harness and Rear Door harness. The not locked connector mentioned above is used in both front door harness and rear door harness, one each. Sorting has been conducted at Delphi Europe for all harness in stock. Totally 50 pieces defective harness were found. Directions - Fill out an initial Is-Is Not form based upon the above information - Any other information needed? - Do not try to solve technical problems in the case study.

A tree diagram used to break up a vaguely stated problem into specific source of causes and finally aims at root cause by crossing-off those that do not matter. It is similar to Shainin's Problem Definition Treesm, Project Definition Treesm, and Solution Treesm. A tree diagram that is mapped down by continuously asking “why” and thinking in the way of “Is-Is Not”. A useful tool for the first meeting and routine meetings of a problem solving team, because it puts the collective group knowledge on paper and shows what information is lacking and still needs to be collected. A systematic way of problem solving by dividing sources of possible causes into logic families, which is powerful and favored by our customers

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Problem Solving Tree How to map a Problem Solving Tree?1. 2. 3. 4. 5.

6. 7. 8.

Start with a summarized problem description, which actually is a project definition. Map the first level of families of possible sources of causes. Break up first level of families into second level of families. Continue above step until the root cause is found. Make splits. (Cross-off those families that are not causes of the specific problem, by using any appropriate tools, including Shainin techniques, DPS tools, 6-Sigma, etc.) Finally point at the root cause. Confirm the identity of root cause. Wrap up the investigation.

Note: Rome was not built in one day. Don’t try to find out the root cause at the first meeting. All eliminations should be done with professional knowledge or experiments.

Problem Solving Tree-Example

See case study “Burnt Relay”

Problem Solving Tree-Case StudyBackground Three pieces of Volvo Frond Door harness(P/N: 8697907) were rejected by VCG(Volvo Belgium Plant) respectively on Sep-23-2004, Oct-12-2004 and Oct-15-2004. The reason for rejection is one connector can not be locked with the mating parts. When the final assembly operators at Volvo tried to mate these harness with mating parts, a clear “click” sound could not be heard, and the mating parts could be easily pulled away from each others, which indicated a non-locked connection. The not-locked situation existed after disassembling and reassembling multiple times. The defective harness was originally built at Delphi GZ, then shipped to Delphi Europe, then transported to Volvo’s plants. Delphi GZ is building both Volvo Front Door harness and Rear Door harness. The not locked connector mentioned above is used in both front door harness and rear door harness, one each. Sorting has been conducted at Delphi Europe for all harness in stock. Totally 50 pieces defective harness were found. Upon measurement to the defective parts, the height of lock latch is found be be out of spec, which can result in a not-contacted or less-contacted locking connection. But, it’s not clear where this failure mode occurs, at supplier’s site, or at Delphi? Direction: Complete a draft problem solving tree based on the above information.

Problem Solving Tree-Case Study

To be skilled with these tools, you need to:

- Learning by doing… - Draw a problem solving tree the first time, every time… - Think in the way of “IS-IS NOT” and keep asking “WHY”…